Orbital sander



2 Sheets-Sheet 1 June 25, 1957 F. w. MOORE ORBITAL. SANDER Filed Nov.15. 1951 l11111111111111111111lfllllllllll F. W. MOORE ORBITAL SANDERJune 25, 1957 Filed Nov. l5, 1951 2 Sheets-Sheet 2 Gttorneg UnitedStates Patent() oRBI'rAL SANDER Fred Williams Moore, Greenfield, Mass.,assigner to lviillers Falls Company, Greenfield, Mass., a corporation ofMassachusetts Application November 15, 1951, Serial No. 256,500

2 Claims. (Cl. 51-170) This invention relates to sanders.

An object is to provide a sander in which the sander block is driven byan eccentric, with the provision of a connection between the sanderblock and a xed point on a power source whereby the movement of theblock is modified to an orbital movement which markedly increases theefficiency of the operation upon the work.

A further object is the provision of a sander having a linkage of simpleconstruction without the use of resilient members of rubber or the like,to support the sander block in its orbital operation, which by reducingthe amplitude of its movement to a practical minimum, will substantiallyreduce wear and make for long troublefree operation.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combinations of elements and arrangement of parts which will beexemplified in the constructions hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

Figure 1 is a schematic view on a reduced scale showing the sander, itshand grip and the power lead.

Figure 2 is an enlarged View showing the connection from the power motorto the sander block in section taken on the line 2 2 of Fig. 3.

Figure 3 is a section on a reduced scale on the lines 3 3 of Figure 2looking in the direction of the arrows.

Figure 4 is a fragmentary isometric detail of the connection between thesander block and the power frame for imparting the orbital movement tothe sander block.

Figure 5 shows schematically on an exaggerated scale the sander block inone position and its connected linkage in the corresponding position.

Figure 6 shows a position in which the eccentric driven by the power hasmoved through an angle of 90 degrees in a clockwise direction and thesander block has moved through an arc which has brought it to theposition shown.

Figure 7 shows the position of the parts, as the eccentric has moved ona further 90 degrees.

Figure 8 shows the position as the eccentric has moved through a furtherangle of 90 degrees and with the completion of the cycle of theeccentric shown in Figure 5 referred to above.

Figure 9 illustrates the extent of movement of the various parts shownin Figures 5 to 8 and graphically shows the negligible vertical movementof the sander block displacement.

The sander is driven by a power motor and the illustration shows theframe of an electric power motor, A, having a hand grip, B, and powercable, C. Carried by the motor frame A, is a depending hood, D,connected to the motor frame, A, by a set screw pin 1. A shaft, 2,

2 driven by the power motor is screwed into an eccentric, 3, which ismounted, as by the anti-friction ball connection shown, in the sanderblock 4 the outer race of the bearing assembly shown is rigidly securedto the sander block 4 and the inner race of this assembly is rigidlysecured to the eccentric 3. On the sander block the sander strip 5 ismounted with an interposed sponge section 6. Spring pressed pivotedlevers 7 are shown for holding the sander strip in place, and areprovided at their extreme ends with hand grips for hand operation torelieve the sander strip for replacement.

While in this instance the operating material is shown as a sander stripthis may be replaced by some other polishing or buiing material or othermaterial may be carried directly by the sander block or the spongesection.

A U-shaped rod 8 is pivotally mounted upon the sander block 4. As shownit passes through sleeves 9-9 carried by the block. This rod, which maybe in the form of a relatively small wire, has substantially equal arms10 extending upwardly at each end terminating in eyes 11 at their upperends through which pass pins 12 so that there is a pivotal connectionbetween arms 10 and the downturned ends of bar 13. Bar 13 is pivotallyconnected `to parallel bars 14, and bars 14 are pivotally mounted onscrew pins 15 which are secured to the hood D. A further bar 16 is shownconnecting the two screw pins 15 but this is not essential.

By the construction shown, the motion of the sander block is convertedinto an orbital motion of which four degree positions are shown inFigures 5 to 8. This results in much more eiiicient sanding of the workand limits gouging, or other mar-ring of the work.

The operation of the machine will be largely obvious from thedescription already given. When power is supplied to the motor, theoperator grasping the handle B can apply the machine as desired to thework with the result in orbital motion illustrated. Since certainchanges may be made in the above construction and dilerent embodimentsof the invention could be made without departing from the scope thereof,it is intended that all matter contained in the above description orshown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which as amatter of language might be said to fall therebetween.

I claim:

1. In a sanding machine in combination a sander block carrying a sandingmaterial, a frame, a pwer driving means carried by said frame, aneccentric driven by said power means and connected to actuate saidsander block, a sleeve mounted upon said block, a U-shaped rod havingits base passing through said sleeve whereby its arms are free forswinging movement with relation to the block, a rigid link spaced awayfrom and extending across said block near one of its ends, the outer endof one arm of the rod being pivotally connected to one end of said linkforming a junction therewith and the outer end of the other arm beinglikewise connected to the other end of said link forming a secondjunction, and parallel rigid members having the forward end of one ofthem pivotally connected to one junction between said arm and link andthe forward end of the other of them pivotally connected to the otherjunction, and the other ends of the parallel members being pivotallyconnected to the frame.

2. In a sanding machine in combination, a sander block carrying asanding material, a frame, a power driving means carried by said frame,an eccentric driven by said power means and connected to actuate saidReferences Cited in the le of this patent UNITED STATES PATENTS KehleJan. 20, Swank Oct. 26, Champayne Nov. 16, Champayne Jan. 23, Osman May11, Dobson Aug. 8, Crosby Mar. 20, Robins Oct. V21,

